I have a freshly re-manufactured Motorcraft 2100 2 barrel carburetor that was on my 73 Mustang when I purchased it. Although one of the first things I did was ditch the stock intake manifold and 2 barrel for a 4 barrel carb setup, I had done a rebuild kit on the 2100. It may seem silly, especially since the carb looks brand new, but I wanted to rebuild it for the experience and getting to become comfortable with the various parts and workings of a carburetor.

Turns out my dad has four of these carbs laying around, and I found out one of them has the rare 1.33 Venturi size. As far as I can figure out, this is the largest that was made, coming in at roughly 424 CFM versus the 1.21 I have that pulls 351 CFM. Problem is the 1.33 is in real bad shape.

So my question is, what parts are interchangeable? What parts are not? For example, can I swap air horns without effecting the 424 CFM rating?

The throttle body, air horn, and venturies are built for the specific cfm capacity, which is the bulk of the carb, in addition the air bleeds and I sure several other components are different, I not saying parts don't look the same and parts can't be swapped, what I'm saying if this is higher cfm carb, it won't work properly if you swap or mismatch parts with a lower cfm carb, clean it up and rebuild it, which sounds like a difficult job, it's only value might be its rarity, but from a performance standpoint it is obsolete, a four barrel carb will outperform it easily. And one final note, two barrel carbs are rated differently than 4 barrel carbs on cfm. Good Luck.

The throttle body, air horn, and venturies are built for the specific cfm capacity, which is the bulk of the carb, in addition the air bleeds and I sure several other components are different, I not saying parts don't look the same and parts can't be swapped, what I'm saying if this is higher cfm carb, it won't work properly if you swap or mismatch parts with a lower cfm carb, clean it up and rebuild it, which sounds like a difficult job, it's only value might be its rarity, but from a performance standpoint it is obsolete, a four barrel carb will outperform it easily. And one final note, two barrel carbs are rated differently than 4 barrel carbs on cfm. Good Luck.

Thank you, I was afraid of that... I've already begun cleaning it and have a rebuild kit, it's just really rusty and grimy to the point where I'd have to believe it'd effect performance plus it's on there good!

As for it being obsolete, I understand, just wanted to tool around with it and if I ever (so whatever reason) wish to keep a 2 bbl set up, I'd have a pretty decent one on hand.